Artificial hand and means for actuating the same



Aug. 14, 1945. F. v. E'BIERLE 2,382,403

ARTIFICIAL HAND AND MEANS FOR ACTUATING SAME.

Filed May 21, 1942 INVENTOR, FE/HVK KZBEEL:

Patented Aug. 14, 1945 ARTIFICIAL HAND Ass M JANSFO IL AQTUATING THE SAME Frank Eberle, Newark, N. J.

Application May 21, 1942, Serial 8. 443,889

" (orbs-I2) I 2 Claims.

This invention relates to artificial limbs and more particularly to an improved artificial hand and means for actuating the same. i

One of the objects of the inventionis to provide an improved artificial hand which is .im-

mediately responsive even to minor impulses of the actuating muscles functioning by means: of a cineplastic operation. I I 1' Another object is to provide an improved artificial hand of simple and economical construction by means of which complete closing and opening of the fist can be accomplished with a minimum of effort.

come one of the most vitalproblems of our pres ent age. The daily toll taken by trafiic and industrial accidents will be increased by recent developments. Those who suffer-permanent injury and loss of limb will have to be rehabilitated by means of vocational training and physical restoration of the lost powers so as to enable the handicapped person to earn a livelihood.

Artificial appliances have heretofore been used to replace the missing member. However, because of the unsatisfactory experiences with the ordinary mechanical limb, attention-has been directed toward the development of a substitute limb in which the control can be achieved by natural muscular action. In order to accomplish the intended purpose, it is imperative that the artificial limb be highly sensitive and immediately responsive to even minor impulses produced by the controlling muscles. In many instances, particularly in connection with amputations im- F igure 2 is a top plan viewrwith the top plate removed; 1 a V v. "Figure 3 is a detailedqview of the-locking: mechanism; 1 H i Figure 4 is a perspective view showing the artie ficial hand illustrated; in Figures 1 and zconnected to the stump andwherein the prosthesis is activated by the muscles after a cineplastic operation. t j Referring in detail to the drawing, the frame or casing; it) represents the palm and the back ofjthe hand. ,The front portionoi the casing I0 is provided with an opening it inwhich the knuckle portions of the fingers I 2 are pivoted on the shaft l3. r i

a; The thumb I4 is similarlypiv oted in t heopen ing IE to the shaft l6; p

1 An actuating lever l H extends from the knuckle portion of the "fingers [2 into the casing H]. A corresponding'lever !8 extends from the thumb M in opposite relationshipto the lever; 11.. The

' lever l1 and. I8 areso disposed.that their'ends move in substantially parallel planes toward: and awayfrom one another. i t

Aucrank H3 is keyed toithe shaftlll which is rotatably mounted in the. boss 2|. which latter ispreferably cast integrally with the casing ill. I j A link 22 connects the lever I! to the crank 19. A second link 23 connects the lever l8; to thecrank l9. The pivot point of the link 23 is spaced from the pivot point of the link 22 on the crank IS) for the purpose of adjusting the relative movement between the fingers l2and the thumb-l4. I Thecrank ,49 is actuated bylinear movement of thevrod 24 which is pivoted to the pin 25 which, in turn, is anchored to the crank I9. To the shaft 20 is also keyed the toothed segment 26 so as to move jointly with the crank I9.

mediately above the wrist, the muscles lose prac- .tically all action and have to be re-educatedl.

It is, therefore, the particular purpose of the present invention to provide an artificial limb in which prosthesis can be activated by these muscles.

The invention can be used with particular advantage in connection with cineplastic amputations. In this type of amputation, pegs are passed through the canals in themuscles and attached to levers operating the artificial hand mechanism. The flexors and extensors in the lower arm control the grasp and release the fingers of the artificial hand.

In the drawing: v I 1 i Figure 1 is a cross-sectional view of an artie ficial hand according to the invention with the adjacent portions of the wrist and the actuating lever mechanism;

Forreinforcement purposes the. pin 25. preferably is anchored to the toothed segment 26. The

pawl 21 which is adapted to engage the-toothed segment 26 is pivoted at 28 to the lever; 29 whic h, in turn, is journaled upon the-shaft 20. x A p t The lever 29 is provided with an-arm 3|,the end of which is connected to the inside. ofthe casing H) by means of the spring 32;: Another spring 33 connects the arm 3| with the pawl 2l.

By virtue of this construction, the pawlwill become disengaged from the toothed segment 26 immediately upon release of the locking mechanism which will be hereinafter described; and jump back to its normal position. The arm. constituting a part of the lever 29 limits the return movement of the lever 29 bystriking again the underlying surfaceof the casing Ill. t

The locking mechanism comprises an eccentrio 35which is pivoted at 36 to the boss 31. The eccentric is rotatedby thelever 38 whichprojeots into thepalm through the opening 39 in the cas ing. The link 40 is pivoted at one end to the rotate the segment 26 together with the crank .l 9'

and thus bring the segments l2 and the thumb l4 closer together. By reason of this construction the force of the grip can be increased once contact has been made between the object and the fingers and the thumb. It will also be understood that the fingers and thumb can be locked I able with said rod and connected to said crank, a pawl for engaging said rack, a leverage mechanism' connected to said pawl for moving said rack a predetermined distance, a two-armed lever pivoted to said pawl, a spring between said lever and said pawl whereby said pawl will be disengaged from said rack immediately upon release of said leverage mechanism, a second spring bein any position intermediate the fully opened and of the drawing, the rod 24 is movedby the lever 44 which is pivoted to the bracket 45 carried by the wrist collar 4|. The other arm of the lever 44 projects through the slot 46 in the cuff 42 and is pivoted to therod 41 which, in turn, is connected to the shackle 48. The ends of the shackle 48 are connected to the peg 49 which is passed through the canal in the extensor muscle.

The lever 44 is provided with a rocker arm 5|] to which is pivoted the link 5| which, at the other end, is pivoted to one arm of the bell crank 52 which, in turn, is pivoted to the bracket 53, extending from the wrist collar 4|.

the cuff 42 and is pivoted to the rod 55, which is connected to a shackle 48a similar to the shackle 48 and situated on the opposite .side thereof, which is connected to a peg 49a passed through the fiexor muscle in a manner similar to peg 49.

The hand is operated as follows: The extensor muscle will rock the lever 44 in the direction shown by the arrow'in Figure 1 which will, in turn, push the rod towards the fingers. The movement of the rod 24 will rotate the crank l9 towards the fingers and the leverage arrangement will cause the fingers and thumb to spread apart.

An impulse from'the fiexor muscle will move the crank bell 52 in the direction of the arrow in Figure 1. This movement will be transmitted to the rocker arm 5|] through the link 5| and thus cause the rod 24 to be returned to its original position.

What is claimed is:

.1. An artificial hand to be actuated by the movements of two pegs of the class described, passed through suitable muscles of an arm stump and controlled by contractions of said muscles,

said hand including a frame, a series of fingers and a thumb pivotecLto said frame, a pair of arcuate levers connected to said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their free ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, links connecting each of said levers a to said crank, said links being so disposed as to transform the linear movements of said rod' into pivotal clamping and unclamping movements of said fingers and said thumb, a toothed rack mov- The other arm of the bell crank projects through the slot 54 in tween said lever and said frame for locking said pawl in a predetermined position of said leverage mechanism, a longitudinally movable bar, means pivotally connecting one end of said bar to one end of one of said pegs, a second longitudinally movable bar pivotally connected with one end to the other one of said pegs, a pivotally arranged bell crank having one arm pivotally connected to said longitudinally movable rod and a second arm pivotally connected to the other end of said first bar, and means operatively connecting said second longitudinally-movable bar with said bell ,crank, whereby longitudinal movements of one of said bars cause longitudinal movements of said rod in one direction and longitudinal movements of the other of said bars cause longitudinal movements of said rod in the opposite direction.

2. An artificial hand to be actuated by the movements of two pegsof the class described, passed through suitable oppositely locatedmuscles of an arm stump and controlled by contractions of said muscles, said hand including a frame, a series of fingersand a thumb pivoted to said frame, a pair of arcuate levers connected to-said fingers and thumb to open and close the hand, said levers being disposed in opposing relationship with their. free ends movable in substantially parallel arcs, a crank, a longitudinally movable rod for actuating said crank, links connecting each of said levers to said crank, said links being so disposed as to transform the linear movement of said rod into the pivotal movement of said fingers and said thumb, a toothed rack movable with said rod and comiected to said crank, a pawl for engaging said rack, a leverage mechanism connected to said pawl for moving said rack a predetermined distance, a two-armed lever pivoted to said pawl, a spring between said lever and said pawl whereby said pawl will be disengaged from said rack immediately upon release of said leverage mechanism, a second spring between said leverand said frame for locking said pawl in a predetermined position of said leverage mechanism, a longitudinally movable bar connected with one end to one of said pegs, another longitudinally movable bar connected with one end to the other one of said pegs, attached to the base of said frame, a three-armed bell crank pivotally disposed within said sleeve, said bell crank having one arm extended through said sleeve and pivotally connected to the other end of said first bar, and a second arm pivotally connected to said longitudinally movable ro'd, a two-armed bell crank pivotally disposed within said sleeve, said two-armed bell crank having one arm extended through said sleeve and pivotally connected to the other end of said second longitudinally movable bar and. a link pivotally connecting the third arm of said first bell crank to the second arm of said second bell crank, whereby longitudinal movements of one of said bars cause longitudinal movements of said rod in one direction and longitudinal movements of the other of said bars cause longitudinal movements of said rod in the opposite direction.

FRANK V. EBERLE. 

